Anyone use the CTEK 7002 charger for an extended period of time? My 2011 M3 has to sit in the garage for about a month (unattended) and I was going to hook up the CTEK to the battery terminals in the engine bay. I have not done this before for an extended period. Is it completely safe? Thanks.

The 2011's and maybe earlier have a "glass" battery, the 3 letter acronym escapes me right now. I think it's AGM. Anyway from what I've read you have to use a particular type of trickle charger on these types of batteries. I think that CTEK is the right kind though. Do your research. Good luck